Zeolites to catalyze dehydration of lactic acid to acrylic acid

FRANCISCO GONZÁLES PEÑA; CRISTINA L. PADRÓ; CARLOS APESTEGUIA

Munich

Congreso; 15th International Congress on Catalysis; 2012

Dechema

Acrylic acid and its esters are primary building blocks of all acrylate polymers and plastics. Currently, 100% of acrylic acid (AA) is produced from fossil oil, mostly via direct oxidation of propene. Lactic acid (LA) can be produced by chemical synthesis or by fermentation of different carbohydrates such as glucose (from starch), and the production of lactic acid is around 350 000 t/year. Therefore, the production of acrylic acid via dehydration of lactic acids (LA) is an attractive method for creating new bio-based compounds.The aim in this work was to study the dehydration of LA to produce AA with different solid acids.The infrared spectra of adsorbed pyridine was used to determine the concentration of Lewis and Brønsted acid sites, and TPD of adsorbed NH3 was performed to determine the density and strength of solid acids. The dehydration of lactic acid was carried out over a fixed bed reactor at 583K, using solid acids with different acid properties such as Na(Zn,H)Y, NaZSM5, KL and γ-Al2O3Allyl-lactates were detected inthe analysis of the condensate product sample from the lactic acid dehydration. These products were identified using a MS-GC.The tentative pathways to form these species are shown in fig. 2. We summarized these oligomers (LA2, LA3 and LA4)of lactic acid as LAL. Incorporation of cations in NaY zeolites increased the total acidity, and changes the concentration of Lewis and Brønsted acid sites